Fuel pump



Jan. v7V, 1,930. H, G, KAMRATH v 1,742,770

FUEL PUMP Filed June 271 1928 Patented Jan. 7, 1930 uNirED STATES PATENT oFF-ica HERBERT G. KAMRATH, OF FLINT, MICHIGANLSSIGNOR TO A C SPARK-PLUG COMPANY, OF FLINT, MICHIGAN, A COMPANY F MICHIGAN FUEL Application led June 27,

As will be understood from the above title,

this invention relates to fuel pumps such as are currently employed upon automotive vehicles, and elsewhere in connection with internal combustion engines; and it is a particular -object of this invent-ion to provide simple and effective intermediate means for the transmission of motion from a pump actuating element, such as an oscillating lever, to a pump diaphragm or the like.

' Although the present invent-ion is herein described `with particular reference to a diaphragm pump of the general character describedand claimed in a pending application of Abraham M. -Babitch, Ser. No. 123,370, led July 19, 1926, it should be understood that the principles of said invention are believed to be applicable to other reciprocatory pumps in which provision-may be made for use of resilient means to eectan expulsion stroke of a pumping element, the intake stroke thereof being positively effected but variable in length,diminisbing as a pressure is built up by the operation of the pump.

Other objects of this invention, all forms of which involve the use of some flexible but substantially inextensible linear element interposed between a part such as a so-called diaphragh stem and a rotatingor a reciprocatory actuating element, may be best appreciated by the followin description of an illustrative embodiment t ereof, taken in connection with the appended claims and-accompanying drawings. p

Fig. 1 may be referred to as a substantially median verticalsection through a fuel pump illustrating this invention'.

Fig. 2 is a partial view corresponding to a central portion of Fig. 1 but showing an al- .40 ternative form.

Referring rst to conventional parts of the fuel pump illustrated in Fig. 1, a mainstructural element in the form of a body casting 1 and a subsidiary structural element .45 in the form of a cover casting 2v are shown a's cooperating in tlie retention of a flexible diavphragrn 3, adapted to serve as reciprocatory pumping element,-eiective to vary the cubic contents of a pump chamber 4, shown as pro-l vided in the cover casting. 2.

PUMP

1928. Serial No. 288,780.

The cover casting is shown as provided not only with inlet passages 5, 5', 6-and 7 and with outlet passages 8, 8 but also with means for supporting a filter cup or sight cup 9, adapted to retain ilteyrs 9.

An oscillable actuating element in the form; of a lever 10, pivoted at l1 to the main castmg 1, is shown as engageable by some moving' part,-which may be, for example, a cam 12 on a camshaft or a crankshaft 13, or some other rotated or reciprocatory element. Means such as a compression spring 14, interposed betweena cupped disc 15, secured at the bottom of themain casting 1, and an oppo- 'sitely cupped disc 15', engageable b'y an in- C3 vner end or arm 21 of the lever 10, may be employed resiliently and constantly to hold the opposite end ofsaid lever in engagement with the cam`12. 4

Inlet valve 16 and outlet valve 17 being provlded in the respective passages leading to and from the pump chamber 4, and the diaphragm 3 being suitably "attached to a handling part such as a slidable rod or so-called dlaphragm stem 18, the present invention more particularly relates to -novel and advantageous means, interposed l between the diaphragm handling element 18, or its equivalent,vand a portion such as the inner end 21 of an actuating element 10.

For the purpose last referred to, a flexible but substantially inextensible linear element 22` which may be a suitabletape, a leather.

l or textile or woven wire strip, ior even a thin and pliable strip of metal, or the like, may be 85 attached at or near' its ends, and in any suitable way, to terminal portions of the diaphragm stem 18 and the lever arm 21. For example, use may be made of means such as a,

bolt 23, shown as extending .through a reduced and rounded terminal portion of the stem 18, and a screw 24, shown as extending into the end of the lever arm 21 (optionally rounded somewhat assuggested at 25) and the length of the element 22 may be such as 95 to produce a complete intake movement of the reciprocatory pumping element V3 during each rotation of the cam 12, unless this pumping element is held down by pressure built up within the'chamber 4. The described 100 parts are so related that each reciprocatory movement of the arm 21 may, however, produce a fieXing or buckling of the strip 22, somewhat as suggested by the dotted lines 22'; and it is accordingly important that said strip be formed of a material that can under` go repeated bending Without avoidable deterioration.

In the alternative embodiment of this invention shown in Fig. 2, the lower end of a diaphragm stem 18a and the inner end 21a of a lever 10a being respectively slotted and provided with transverse pins 27a, 28a, these pins are shown as connected by a flexible but substantially inextensible thrust-refusing intermediate element in the form of a woven or twisted cord or cable 29a,-the ends thereof being shown as looped about the respective pins 27a, 28a, and as suitably wrappedy at 30. The construction here referred to is such that, whether or not the respective ends of the exible element 29a undergo a slight rotative movement during each reciprocation of the lever 10, or its equivalent, said element 29a may be fiexed, substantially as indicated by the dotted lines 29a', at such times as the up-` ward stroke of the' diaphragm stem 18a may be prevented by the building up of a pressure within a pump chamber. c

As compared with thrust-refusing intermediate means in the form of rigid links, the above described use of a linear element in the form of a single length of lap of a mate rial which is so iiexible as to bend under thrust but so inextensible as to reliably transmit a tension has the important advantage of complete silence during operation, and, unless the mentioned flexible element is formed of resilient material, neither, its weight nor its elasticity need'be'taken into consideration in the calibration of the spring 19 or the spring 14, for a desired effect. It is an obvious merit of the illustrated mode of attachment of the desired linear elements that the resultant bends therein are slight when said linear elements are under tension. The suggested rounding of corners engaging said linear elements may accordingly be regarded as optional, and the exact mode of attachment of the mentioned ends may beregarded as a matterof vsubordinate importance,-assuming that 22 is not a part of 18.

Although the foregoing'description has included but two embodiments of the present invention, it will be obvious that numerous additional modifications might easily be devised, Without involving the slighest departure from the spirit and scope of the invention as the same is indicated above and in the following claims.

I claim:

1. In a pump of that type which includes a pressure-responsive reciprocatory pumping element, movable in Ione direction in a pump y chamber by means including an attached part and conditionally advanced in the opposite direction by resilient means: actuating means having a uniform throw; and inter-- mediate means, in the form of a single-length linear element formed of a substantially inextensible material, so flexible asl to bend under thrust but so inextensible as to transmit a tension, interposed between and terminally secured to said attached part and said actuating means andthereby serving to lmpart variable strokes to said attached part.

2. In a pump of that type which includes a pressure-responsive reciprocatory pumping element, movable in one direction in a pump chamber by' means including a slidable rod and conditionally. advanced in the opposite direction by resilient means: actuating means having a uniform throw; and intermediate means in the form of a single-length linear element formed of a substantially inextensible material, so flexible as to bend under thrust but so inextensible as to transmit a tension, interposedbetween said slidable rod slight when said linear element is under tension.

In testimony whereof I affix my signature.

HERBERT G. KAMRATH. 

